'Americans' spy hunter has scruples and flaws.

• Author: Moore, Frazier
• Position: Living

Byline: Frazier Moore

NEW YORK -- "The Americans'' puts its audience on the spot.

Who to root for?

Do we throw our support behind Elizabeth and Philip Jennings (played by Keri Russell and Matthew Rhys), the sexy, all-American-seeming couple who in truth are Russian-born KGB spies working to bring down the United States from within?

Or do we side with Stan Beeman, their neighbor in a Washington suburb, who happens to be an FBI agent in this circa-1980s phase of the Cold War? Stan (played by Noah Emmerich) is sworn to flush out these enemies of the state, but, despite his smarts and dogged commitment, he is constantly frustrated in his mission while undermined by personal demons.

As "The Americans'' returns for its second season at 10 p.m. Wednesday on FX, the continuing obligation for its fans will be to reconcile divided loyalties and cheer for both parties, never mind that they're working in deadly opposition.

As before, viewers will likely thrill at the death-defying dedication of Elizabeth and Philip, but will identify with Stan. In Emmerich's performance, he sticks to a fine line between being a hero and being a dupe. He's a straight arrow bending under the pressures of his job, including the isolation it imposes: He has lately fallen into an affair with a beautiful Russian informant as his job keeps him from home.

Most challenging for the audience to deal with: Stan is largely unknowable. Unlike Elizabeth and Philip, whose secret lives are manifest to viewers, Stan remains a private soul to all.

"You don't know what he knows,'' says Emmerich. "You don't know what he's thinking.''

Stan's early-on suspicion of Elizabeth and Philip seems to have relaxed into acceptance of them as the ordinary couple they pretend to be. In a future episode, he even meets Philip at a bar for a sodden heart-to-heart about his extramarital affair.

"I haven't told anybody,'' he tells Philip in a near-whisper. "So you can't.''

Has he let down his guard beyond the point of return?

"Is he naive? Or is he...